Some things are pretty much cast in stone on St Patrick's Day and one of them is that Blackrock are crowned Leinster Schools' Senior Cup champions at Lansdowne Road. Yesterday they were more than entitled to claim their 63rd cup.

With the rest of the province's schools cobbling together 50 cups between them, there's no doubting Blackrock's pre-eminence. Whatever the formula is in Williamstown, success clearly breeds success.

This year's crop proved themselves worthy champions and inheritors of the Blackrock mantle. They're a skilful, talented all-round side, indeed there's something of the 'Rock of old about them, and this year's Coca Cola-sponsored final was better than most. Although a typically durable Roscrea outfit came back gamely in an absorbing second half to close the gap to a point, ultimately a deserving Blackrock adorned the occasion with all three tries.

All of them came from backs, who've scored nine of Blackrock's 16 tries in their five matches during this campaign, and there might well have been a few more too. The twinkle-toed, elusive left-winger Alex Cahill danced along the touch-line repeatedly in the second half to the delight of the Blackrock supporters among the 15 to 20,000-strong crowd and with a different referee might well have had two tries to his name.

Blackrock weren't afraid to run the ball from the surprise zone inside their own 22 and you could have closed your eyes and imagined that this is how the school was accumulating senior cups aeons and aeons ago.

Out-half Andrew Frame, emulating his father in 1959 and brother in 1990 by gaining a third cup-winners medal for the family trophy cabinet, was forever willing to spin passes flat across the gain line. Outside him, they were all accomplished runners, with pacey centre Gary Brown scoring the try of the match and Conor Buckley also catching the eye along with fellow winger Cahill.

This greater cutting edge out wide always gave them a more potent look. But for a few marginal decisions against them, they could well have broken out for a couple of long-range tries. In truth, they probably deserved it, although by the same token that would have been hard on the all-blacks from Roscrea.

A little overawed in the opening period, Roscrea could hardly get a foothold in the game. Their lineout maul was virtually negated by Blackrock's strategy of contesting with two jumpers, number eight Shane Fallon being responsible for pilfering many of the seven throws Roscrea coughed up.

But their impressive Kiwi coach, Kevin West, regrouped them superbly at the interval. Their pack's pick-and-go surges yielded big dividends, and they put Blackrock on the back foot for lengthy spells. Few can have done more in a losing cause than open side flanker Barry McCann. He seemed to be everywhere, repeatedly breaching the gain line from popped passes, while also tackling and supporting well.

Sean Byrne, Patrick McCarthy and John Phelan also had good yardage hauls, as did Gavin Duffy and Redmond Barry outside of them. But the surges were eventually stemmed by enforced turnovers as Blackrock refused to give up anything other than a few penalties to Barry's trusty right boot. Blackrock were just that bit classier and more streetwise.

Still, this wasn't just Blackock's day. The Roscrea boys, assembled in front of their own supporters to the right of the celebrating blue-and-white thousands before the medal ceremony, were entitled to the roars that briefly drowned out the victors. They've come a long way.

Careful planning and husbandry has ensured that Roscrea have arrived as something of a force in Leinster schools' rugby. And Leinster schools' rugby is all the better for that.

However, from the moment the team lined up in front of their supporters in the West Stand for a pre-match anthem, you sensed that Blackrock weren't going to miss out yesterday. Even then it seemed a few of them were about to pop a few blood vessels. This was serious.

Admittedly their first scrum was in a bit of bother, and Barry drew first blood for the underdogs with a mighty 45-metre penalty after six handling errors had contributed to seven turnovers in the first nine minutes.

Blackrock camped in the Roscrea 22 from the restart and tight-head John Montgomery nearly pierced the Roscrea pack before eventually, and inevitably, they struck. Scrum-half John Walsh worked a couple of one-handed dummy scissors on the blind side and darted through a gap. Though tackled, he stayed upright, looked for support, found none and stretched out for the line. Pretty cool stuff.

Their next try, within three minutes, was all about keeping the ball alive in the tackle and supporting runners in broken play.

Though Walsh and Frame were going backwards, they kept the move going for John Ronan cleverly to explore the blind side, and after Buckley had run positively onto Montgomery's inside pass, Ronan was in support to score a fine try in the corner.

You feared for Roscrea then, but they're not inclined to roll over and have their bellies tickled. They had to wait all of 33 minutes for their first line-out ball, and then Blackrock's pack held up the drive from Dan Cavanagh's take to earn a relieving penalty.

Even so, Roscrea immediately picked up the tempo upon the restart. McCann began breaching the gain line with even more gusto closer-in, and ditto Duffy wider out as Barry reduced the arrears to 10-6 with his second penalty.

Quick to pounce on turnover ball, the Blackrock threat remained, as first Cahill was denied what seemed like the touchdown to Frame's blind side chip by the retreating Shane Connellan, and then slightly overran Brown's pass after Frame delightfully released the centre from the 22.

Nevertheless, substitute scrum-half Gordon Ross added even more momentum to Roscrea's drives, as the more utilised Phelan, McCann and McCarthy kept hammering away and after Duffy had charged up the middle once more, Ross was late tackled for Barry to make it 10-9. Game on.

Credit to Blackrock, far from panicking, the mini-crisis brought out the best in them. They kept seeking to spring Cahill, and then switched the point of attack to Buckley on the other wing. Again the pass in the tackle found Brown supporting on his inside, after his feigned pass transfixed the blacks, he darted through a gap from 35 metres out and arced around the posts to make Drew's conversion more kickable.

That, to all intents and purposes, was that. Cahill kept on dancing, and was denied another try when brilliantly picking up a pass by their impressive captain Tom O'Donohoe after Frame and Brown had created the space. But six minutes of injury time only delayed the inevitable as the blue and whites converged on pitchside.

"No time for losers, 'cos we are the champions." Ne'er a truer word.

Scoring sequence: 11 mins: Barry penalty 0-3; 18: Walsh try 5-3; 21: Ronan try 10-3; 38: Barry penalty 10-6; 52: Barry penalty 10-9; 59: Brown try, Drew conversion 17-9.

Blackrock College: P Drew; C Buckley, G Brown, J Ronan, A Cahill; A Frame, J Walsh; P Dowling, D Laide, J Montgomery, J MacGovern, R Lacey, M Cooney, T O'Donoghue (capt), S Fallon. Replacements: R Molloy for Walsh (60 mins); J Danagher for Dowling (44-53 mins and 64 mins).

Cistercian College Roscrea: R Barry: E Fox, G Duffy, D O'Keeffe, B Phelan; N Moloney, S Connellan; S Byrne, J Phelan (capt), B Hall, D Cavanagh,, A Spring, P Corcoran, P McCarthy, B McCann. Replacements: G Ross for Connellan (42 mins); M Fleming for O'Keefe (48 mins).

Referee: T Redmond (Leinster).